The invention provides an improved method of graft polymers comprising providing an emulsion comprising at least one or more first monomer (a), at least one or more second monomer (b), and at least one graft material (c). The emulsion is subjected to conditions such that it undergoes simultaneous free radical polymerization and grafting. One or more first monomer (a) is unsaturated and is free of any functional groups reactable with a functional group Fb of monomer (b) or a functional group Fc of graft material (c). Monomer (a) may optionally comprise a functional group Fa which is not reactive with either functional group Fb or Fc. Monomer (b) is unsaturated and comprises a functional group Fb reactive with functional group Fc. Graft material (c) comprises a compound free of unsaturation and comprising a functional group Fc reactive with functional group Fb, and a graft moiety.